Author Bio

Joe Fjelstad, a founder of Silicon Pipe Inc., is an international authority and innovator in the field of electronic interconnection and packaging technologies with more than 185 U.S. patents issued or pending. He is the author of Flexible Circuit Technology and author, co-author or editor of several other books including Chip Scale Packaging for Modern Electronics. He has also authored numerous technical papers and articles. He frequently presents seminars on PCB, flex circuit and chip scale packaging technologies at industry conferences. You may contact him at 408-973-1744, x203.

Flexible Thinking: Profitability—A Vital Design Requirement

Designers have, from the earliest days of the printed circuit industry, been under-appreciated. PCB designs were typically simple, single metal layer affairs, and design activities were considered a mundane (and even boring) task of “connecting the dots;” thus, they were given little respect.

Much has changed over the years, as integrated circuit technology has advanced, and data rates and processor speeds have climbed. Over recent years, I have found myself often saying that designers are arguably the most important people in the development of electronic products. The decisions they make will impact virtually every manufacturing step in the fabrication and assembly of electronics products. The designer’s role is so vital that, over the years, multiple touchstone guidelines have been added to the mix that seek to address myriad concerns that are all part of meeting the goal of producing the best possible products.

“Design for” Guidelines

The first order of concern for any design is that it simply meets the functional goals of the product. This can be accomplished in many ways, but beyond clearing the bar of “Does the product work?” there are many other litmus tests that are being more frequently applied to the evaluation of a completed design. These include design for manufacturing (DFM), design for assembly (DFA), design for testing (DFT), design for the environment (DFE), design for reliability (DFR), design for excellence (DFX), and there are doubtless other “design for” guidelines for other aspects that are deemed important to an individual types of products. All these guidelines provide important considerations relative to the product design in review. When applied, all of these “design for” guidelines combine to create products that can be made both reliably and profitably.

Designing for Profitability (DFP)

Good product design is arguably the cornerstone of every profitable product. Make a product that results in a loss or less than optimal return, and you are either headed for bankruptcy or irrelevance. It is possible to make unprofitable products as one climbs the learning curve or to gain or control market share (many governments subsidize products for this purpose). However, you must nevertheless offer the user something new and of perceived value even if the value is short-lived.

In this regard, it is important that designers work collaboratively with those who will be tasked with manufacturing their designs. Too often, designers work in isolation and do not have a full appreciation of the impact of the choices they make. The products they design are fabulously innovative, but if they cannot be built, and built profitably, what value is there in their effort?

Engage Others in the Design Process Early

How do we overcome this? Make sure all stakeholders involved in the manufacturing and testing of the product have input. Such in-put need not be tapped for every new design if the design is very similar to a past product design, but it does not hurt to have a check-list similar to that used by pilots before every flight. It may seem unnecessary, but an experienced pilot only needs to miss one item on the checklist to cause a potential disaster. “Design for” guidelines can help one to create such a checklist to ensure profitability. Finally, there is a need to make sure that the guidelines are followed. Societies have laws and rules for numerous reasons, but perhaps the most important is that they provide for the continuity of the societies themselves. (If not for traffic lights and stop signs, we would likely need to have either hospitals or cemeteries at every intersection.) Guidelines are different than laws, but the impact of not having them could be similarly troublesome. However, rather than a stringent set of dos and don’ts, al-low some discretion, depending on the product and its application. Advances in technology and innovation could be stifled if the de-signer is not allowed to explore the limits from time to time.

Summary

Designers are definitely “at the controls” at the beginning of every new product launch. Their decisions will impact everything that fol-lows their efforts, including the ultimate profitability of the final product. The use of established “design for” guidelines will serve them well in their work to ensure a smooth transition from concept to product and the future well-being of their company, client, or customer. As I have found myself saying with ever-greater frequency in recent years, we must all first do the right things, and then do those things right. It all begins with design.

2020

The decisions designers make will impact virtually every manufacturing step in the fabrication and assembly of electronics products. Joe Fjelstad explains how applying “design for” guidelines can help create products that can be made both reliably and profitably when applied.

We are seeing increasing interest in technologies that will allow one to make electronic substrates in near real-time using additive processing techniques and 3D printers. It is a true game-changer in product development. The surge in interest in additive manufacturing technologies shown in recent times—as indicated by the significant increase in published articles and press releases—suggests that the electronic interconnection manufacturing industry could be on the verge of a manufacturing renaissance.

2019

Standards are frequently viewed as cumbersome nuisances and impediments to progress by those pressing for rapid change. The process of writing, getting approval, and promulgating standards can be arduous and frustrating. It has a lot of similarities to the creation and passage of laws in various government bodies in that there are many opinions and interested parties who engage in the process to make sure that it results in a product that does not damage or favor one solution or party over another.

It is my opinion that the initial driving impetus for the development of stretchable circuits was a bit different than normal, meaning that military and aerospace have traditionally driven the development of arcane electronic interconnection technologies as they did with the development of both flexible and rigid-flex circuits. In contrast, it was a consumer-driven market that appears to have been the gate opener in the form of wearable electronics.

To begin any process, you must first know where you are going. This is true for any project or life pursuit, I believe, and I often try to bring it to mind as I start any new project. With respect to developing products that might benefit from flexible circuit technology, this is no less true. Find out why.

We all have a tendency to stick close to the familiar and use the tools we know to create solutions to problems confronting us; we're only human. Unfortunately, using only familiar tools limits our ability to come up with optimal or even superior solutions. This article will help you avoid some of the traps conventional wisdom doesn't always give guidance on.

In summary, the decisions made by the flex circuit designer when laying out a flex circuit will have an impact that lasts the entire process. By considering how the circuit might fit onto a panel before submitting the design to a manufacturer, it may be possible to save a considerable amount of material and money.

There is an old and familiar adage that goes something like this: “If the only tool in your tool chest is a hammer, you tend to see every problem as a nail.” We all have a tendency to stick close to the familiar and use the tools we know to create solutions to problems confronting us; we’re only human.

2018

Since their introduction, flexible circuits have continued a steady climb from relative obscurity to center stage in the world of electronic interconnections. Today, they are among the most popular choice for solving challenging electronic interconnection problems. Those who use this technology on a regular basis are familiar with the many reasons for the popularity of flex.

Flexible circuits are known by a few different names depending on one’s global location and language: flexible printed circuits, FPCs, flex circuits, flexi circuits, flexibles, bendables and a few others that are application-specific such as flexible heater circuits and controlled impedance cable constructions. While flex circuits are an original and foundational interconnection technology for electrical and electronic products (one of the first patents for electrical interconnections, issued at the turn of the last century, was arguably a flexible circuit), over the years there have been several forays into technological extensions of the basic idea.

2017

The industry at large needed to jump on the learning curve and overcome its fear of the unknown. One of the most vexing concerns at the time (an arguably still today) is that terminations beneath the area array package were unseeable. Given the fact that then, as today, solder joints were a major cause of failure, there was much consternation over the quality of the joints.

2016

Process engineers serve a vital function on the front line of printed circuit manufacturing. They are often, if you will, the “Delta Force” that subdues and controls that which is one of the mortal enemies of manufacturing…process variation.

2015

Knowing the value of a product or technology is key to making the right decision. Appreciating the value of an element of business is evermore important as the rate of change surrounding an industry accelerates. This brings us to one of the current buzz subjects in our industry: 3D printing. Understanding what it is and what its value is to a company and that company's ability to improve its place in the industry is vital.

2013

First proposed in 2007, there is a potential electronics industry "black swan" technology quietly being developed and refined. It is one that could greatly and positively impact, at once, the cost, reliability, and environmental friendliness of electronic manufacturing by simply eliminating the soldering process.

Photons are making continuous headway into the world of electronics. One thing that the basic data carriers (electrons, microwaves and photons) have in common is that flexible circuits are being increasingly looked to for help in managing their data transmission function.

2012

Those steeped in flexible circuit design and manufacture for any length of time fully appreciate the long list of benefits that only flexible circuits can offer. Some of the most fundamental benefits of flex circuit technology have been exploited since the earliest days of the technology. Joe Fjelstad explains.

The most common interpretation of the word flexible, as applied to the flex circuits that the industry currently makes, is something capable of being bent repeatedly without breaking. Joe Fjelstad discusses a few other definitions of flexible that are worthy of consideration when using the term, for their ability to unlock new thinking patterns relative to what is flexible.

If one is without a sense of the direction their technology is headed, odds are that they will sooner find themselves on the road to ruin than the road to success. A technology roadmap is a critical tool in helping a company make informed decisions. By Joe Fjelstad.

2011

The stretching of circuits to alternately increase and decrease the length of a circuit has proven useful for electronic products and assemblies for years. Stretchable circuit technology and elastronics are poised to take on challenges that cannot be easily met by flexible circuit technology alone. Keep them in mind next time you find yourself in need of a little more "spring" in your design. By Joe Fjelstad.

The stretchable circuit is an interesting and promising new branch on the flexible circuit tree. The stretching of circuits to alternately increase and decrease the length of a circuit has proven useful for many years. The European Union has funded research in this area through such initiatives as the STELLA project.

2010

The fundamental approach to manufacturing rigid-flex has remained constant for the 40-plus years of rigid-flex history. But is there a better way? What if one could produce a circuit that was rigid throughout the manufacturing process and only become flexible in the final step? In other words, what if one could make a rigid circuit assembly, flex?

According to IPC market statistics, flexible circuits continue to be the brightest sector of the overall printed circuit market. The reasons for this are many but, at the end of the day, it generally boils down to the fact that flexible circuits are an excellent way to solve interconnection challenges in a cost-effective way.

Flexible circuit cables offer some significant advantages for facilitating the movement of data between elements of a system that must also be moved or flexed. However, there is a balancing act involved and there is more than one master to be served to create a system that is robust, reliable and easily manufacturable.

With proper planning, stiffeners can be designed to aid assembly through the designed manufacture of a flex circuit that can be handled as if it were a rigid circuit board. Such constructions can be accomplished by using any one of several methods.

Flexibility, the single attribute that makes flex so attractive, also makes flex circuits more difficult to build. What if we could produce a circuit that was rigid throughout the entire manufacturing process and only become flexible in the final step?